Telephone system.



N0. 69l,665. Patented Jan. 2|, I902.

G. BITTER.

TELEPHONE SYSTEM.

(Application filed. July 18, 1901.)

2 Sheets-Sheet l.

No. 69I,665.

Patented Ian. 2|, I902. G. BITTER? TELEPHONE SYSTEM.

(Application filed July 18, 1901.)

2 Sheets-Sheet L central station.

UNITE STATES PATENT. OFFICE. Y

GEORG BITTER, OF STUTTGART, GERMANY.

TELEPHONE SYSTEM SEEGIFIGATIQN forming part of Letters Patent No. 69] ,66 5, dated January 21, 1 902.

Original application filed August 16. I898, Serial No. 688,683. Divided and this application filed July 18, 1901. Serial No. 63.812. (No model.)

T0 ctZZ whom, it may concern: 7

Be it known that I, GEORG BITTER, a citizen of the Empire of Germany, residing at Stuttgart, in the Empire of Germany, have invented certain new and useful Improvements in Telephone Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art'to which it appertains to make and use the same. 7

This application is a division from my application, Serial No. 688,683, filed August 16, 1898.

This invention relates to an improvement in telephone systems, and in particular to a register and testing system for telephone-e21 changes.

One of the objects of my invention is to provide a register system whereby the registration of a conversationchargeable against a substation will only be made'when a conversation actually takes place betweenthe person at the calling substation and another person at the substation called, as .contradistinguished from those register systems in which a registration is made even where the calling subscriber is unable to obtain a reply from the called substation. I

A further object of my inventionis to provide means for testing the lines of a telephone plant provided with my register system.

With these general objects in view, and some others which will be obvious to those skilled in the art from the description hereinafter, myinvention consists in the features, details of construction, and combinations of parts, which will first be described in connection with the accompanying drawings and then pointed out in theclaims.

In the drawings, Figure 1 is a diagrammatic view of a metallic return telephone system provided with a register and testing system embodying my invention, and Fig. 2 a similar view showing two switchboards embodying my invention.

Referring first to Fig. 1 of thedrawings, the Roman numerals land II indicate two substations having the 1 ine-wires1, 2, 3, and 4', respectively, which are connected to the jacksA A of any desired type, located at the Each line is represented at the central-station switchboard by an annunciator of any desired kind, as indicated at B B.

O 0 represent plugs, the former being an answering-plug and the latter a calling-plug. Eachplug has the usual tip-and-shell'terminals, as indicated at c 0, respectively, arranged to coact with the respective jacksprings of the jacks into which said plugs may be inserted. In addition each plug has a third terminal 0 arranged to enter and fit tightly into a jack-ring arranged in front of each jack, said jack-rings being shown at D D, respectively.

The plug-terminals c are connected by a conductor 5, while the plug-terminals c are .connected by an interrupted conductor having the two parts 6 7, arranged to be electrically connected through an automatic circuitcloser, which will now be described.

E is a switch-lever pivoted at e and provided with a con tact-plate e, arranged to contact with an anvil e The pivotal point e and the anvil e form the terminals of the respective parts 6 and 7 of the interrupted plugconductor. The said switch-lever E is'provided at one end with a beveled portion arranged to cooperate with the beveled face of a nose f, formed on an armature latch-lever F,-pivoted atf and provided with an armature f arranged to be attracted and held by an electromagnet G, whose coil has one terminal connected toan anvil g and the other terminal connected to one pole of a local battery H whose other pole is grounded. The armature-lever F is provided with a contactspring f arranged to engage the anvil g and close a circuit through the coils of the electromagnet G. To the armature-lever is connected a lever J, pivoted atj, the connection between the two lovers being made by means of a linkj of insulating material.

The levers J and F are normally drawn away from the magnet G by means of a suitable spring, as shown atj The lever'J is provided with three contact-points, as shown at j y 7' the latter being arranged to cooperate with a contact device j for a purpose hereinafter described. The contact points j j are arranged to engage at different times either the contact-plate k or the contact-plate k, respectively, which contact-plates are fixed i oo on a two-armed lever K, forming part of a compound circuit; changing device, which also comprises the levers K and K the three levers K K K being connected for simultaneous movement by means of a link k of insulating material, which is pivoted to each of the levers K K K The lever K is arranged for contact with either of the contact-points k or R the lever K with eitherof the contacts k or M, and the lever K with either of the contacts it" k The said lever K is provided with a roller 7c", arranged to engage a projection 6 preferably in the form of a bent spring, secured by one end to the switch-lever E, whereby when the circuit-changer is moved, so as to shift the roller to the left, said roller will engage the projection e and force the switch-lever into engagement with the nosefof the armaturelever. The switch-lever E is normaliydrawn downward by a spring 6'.

The contact-points k and it form the terminals of the operators telepone set, (indicated at L,) while the contact-points k and 7t form the terminals of the clearing-out annunciator M. The levers K and K are connected to the conductors 6 and 5, respectively, by the corresponding conductors 1t and 15.

The register and test circuits and instruments are as follows: The jack-rings of each line are connected bya conductor to one pole of the register-battery N, two of these conductors being indicated at 8 and 9, respectively, and each including the register for its own line, which registers are shown at O and 0, respectively. The opposite terminal of the battery N is connected by a conductor 11 to the contact-point k That terminal 0 of the answer-plug which contacts wit-h the respective jack-ring is connected by a conductor 10 to the pivotal point of the lever J. The corresponding terminal a of the callingplug is connected by a conductor 12 to the battery N and by branches 12 and 12 to the contact-point k and the contact devicej", respectively, a high resistance, preferably a condenser P, being included in the conductor 12 between the battery N and the branch conductors 12 and 12". One terminal of the operators telephone set is connected by a conductor 13 to the same pole of the registerbattery N to which are connected the conductors 8. and 9.

A suitable source of calling-current is provided, as shown at Q, which is connected to any suitable calling key for closing said source onto the plug-conductor cords of the calling-plug, said calling-key being indicated at B.

At each substation the usual telephone instruments are provided, and in addition means for grounding one of the substationlines is supplied. This is done, preferably, by providing at each station a grounded branch 16 17, each ending at acontact-point s s, over which the telephone hook-lever S S may pass when the receiver is removed from said hook, thereby momentarily grounding that substation-line which is connected at one end to the pivotal point of the respective hook-lever S S and at the other end to the tip-terminals c of the inserted plug.

The operation of the apparatus is as follows: Assuming that station I desires to communicate with station II and has called the central station in the usual way, the operator inserts the answer-plug O in the jack of the line to station I and moves the compound circuit-changer in such a way that levers K and K are on the contact-points I0 and 7c, respectively, whereby the central-station telephone set is put in circuit with the substation I over the line-wires 1 and 2, the plug-connector conductors 5 and 6, the branch wires 14 and 15, the levers K and K contact-points 7c and k and the operators set. Upon receiving the number of the station desired the operator then inserts the corresponding calling-plug in the proper jack of the line to the desired station (in this case assumed as station II) and then moves the compound circuit-changer so that its levers K and K are brought upon the contacts k and k respectively, thus cutting out the operators telephone-set L and cutting in the clearing-out annunciator M. This movement of the circuit-changer causes the lever K to bring its roller 76 into engagement with the projection 6 thereby forcing the end of the switch-lever E into engagement with the nosefof the armature-lever F, whereby the two parts 6 and 7 of the plug-conductor are disconnected, and the latter conductor 7 is closed onto the battery H through the switch-lever E, the arenature-lever F, the contact-springf the anvil g, and the coil of the electromagnet G. At the same time the lever J is forced to one side by means of its connection with the armature-lever, and thereby the contact-point is brought against the contact device 9' for a purpose hereinafter described in connection with the description of the testing-circuit. Immediately upon moving the circuit-changer, as just described, the operator presses for a short interval the calling-key R, thus ringing the bell at the called station II, but not atfecting the bell at the calling station I, because the circuit back to the latter station is interrupted between the switch-lever E and the contact point or anvil e If now the called subscriber answers the call by removing his telephone-receiver from its hook S, the latter in moving upward passes over and momentarily contacts with the contact-point 5', thereby grounding his station-line 3 momentarily and energizing the magnet G, the circuit being as follows: from the terminal of battery H over the coils of the electromagnet G, the anvil g, the spring f armature-lever F, switch-lever E, conductor 7, through the respective plug-terminal and jack-spring to the line 3, along the same to the hook-lever S, thence by contact-point s to the ground and back to the battery H through the grounded terminal of the latter. The electromagnet G being thus energized, draws the armaturelever F to one side, and thus releases its nose f from the end of the switch-lever E, the latter being then drawn down by its spring a, whereby the circuit through the electromagnet is broken by the separation of the levers E and F, and the talking-circuit is closed across the parts 6 and 7 of the plug-conductor by the lever E coming into contact with the anvil e and the armature-lever F being drawn to one side by the springj so as to break the contact between the spring f and the anvil g. The talking-circuit will be as follows: from station I over the lines 1 and 2, across the plug-circuits (one limb of which is formed by the conductor 5 and the other by the parts 6 and 7, the lever E, and, anvil e along the lines 3 and 4 tothe instruments at station II. The failure of electromagnt G to move its armature-lever F and release the switch-lever E within a short interval after a call has been sent out to a called substation will indicate to the operator that the called subscriber has not answered his telephone call, whereupon either another call may be sent over the said line or the calling subscriber may be notified and the connections cleared out. Upon the completion of a conversation between subscribers and the ringing-off of either of them the clearing-out annunciator will be dropped and the central station thereby notified, whereupon the operator withdraws the plugs from the jacks.

The manner of operation of the register is as follows: When the answer-plug O is inserted in a jack, the terminal 0' of said plug is in contact with the ring D and the registercircuit is closed at the jack, but is still open at one other point and at only said other point, this open or interrupted circuit being as follows: from the contact-point k over the conductor 11, to the positive pole of the register-battery N, thence along conductor 9, through the magnet of the register 0, to the jack-ring D, over the terminal 0 of the answer-plug, along conductor 10 to the pivotal point of the lever J, and thence to the contact-point j of said lever. In this description it is assumed that the operator has first moved his circuit-changer so as to include his telephone L in the talking-circuit before inserting the plug 0, which is the form of procedure hereinabove described with relation to the talking-circuit. Therefore it will be clear that before inserting the answer-plug into its respective socket the register-circuit will be open at two points only-viz., between the jack-ring and the terminal 0 of the answerplug 0 and between the contact-point k and the pointj of the lever J. The former opening is closed upon the insertion of the answer-plug C on answering the call of the subscriber; but the other opening remains open during all the operations of making a connection and up to the time the called subscriber removes his telephone from the hook to answer his call, or, in other words, until the electromagnet G is energized, as has previously been described, at which time the switch-lever E is released, thus breaking the circuit of the electromagnet G and allowing the armature-lever F to fly back and move the lever J with itself. This movement brings the contact-point j of the leverJ into contact with the contact-plate it of the lever K, and

as the latter is at that time upon the contactpoint it the second opening of the registercircuit is closed and the register operated. Furthermore, the register circuit remains closed until the operator removes the answerplng from the jack upon the completion of the conversation, whereby it is possible not only to use a register which will tally the number of conversations actually had by thecalling-line, but, if desired, to employ a register which will record the duration of such conversations, the latter form of registerbeing especially applicable in those systems where the use of the instruments is charged-for according to the duration of such use. Such a register is shown at O in connection with the conductor 9, while a register which merely tallies the number of conversations, irrespective of their duration, is indicated at Oas included in the conductor 8. a

From the above it is clear that the register device tallies only the conversations that are had by a calling substation, and no registration is made of any mere attempts to call a subscriber. 1

The test-circuits and the manner of making a test will now be described, reference being made to Fig. 2 of the drawings. In this figure two substations are shown at I and II, respectively, and the central exchange is indicated as provided with two switchboards and ing tested is the one to station II, which is shown as already in use, being connected to station I through theleft-hand switchboard, as already described in connection with Fig. l. The substation-circuits from the substation which is supposed to have called theoperator at the right-hand switchboard and the calling-drop therefor have been omitted to avoidconfusion. I

It will be noted that the register-circuit battery N and the condenser P are common to both switchboards. Separate sources of calling-current Q Q are shown for each switchboard i'or the purpose of avoidingthe 'onfusion of circuits; but it is obvious that only one such a source need be used. It will now be assumed that the operator at the righthand switchboard has receiveda call and has which ring represents said line in the righthand switchboard. At the same time the operator listens at the receiver of the telephone set and, owing to the closing of the test-circuit by the contact of the tip-terminal and the jack-ring, a click is heard in the said receiver, whereby the operator is in formed that said line to station II is then in use.

The testing-circuit is as follows: from one 1 terminal of the condenser P along the conductor 12 to the jack-ring D, then along the conductor 8* to the corresponding jack-ring D and from there over the tip-terminal of the plug 0 over the conductor 7 (which corresponds in all respects to the conductor 7 of Fig. 1) to the pivotal point of the switchlever E, along the same to the contact-anvil e thence over a part of the conductor 6 and conductor 15 to the circuit-closer lever K, i

from there through the contactpoint 7656, through the operators telephone set I. and conductor 13 to the terminal of the battery N, and from the other terminal of said battery back to the opposite side of the condenser or other high resistance P. Of course the condenser prevents the current from flowing over said circuit; but the charging and discharging of said condenser will produce the necessary sound in the operators telephone in order to give warning that the tested line is in use. It is obvious that if the line to station II was not in use and the plug C not in the jack D then the testing-circuit would not be complete and the condenser could not be charged by touching the tip-terminal of plug C against the corresponding jack-ring D It will be observed that the conductor 12 of the plug 0 is in connection with one pole of the battery N, (over the condenser P,) and it is to be noted that if the corresponding conductor 10 of the answer-plug C is also maintained in connection with the same terminal of the battery N the testing of the jack-ring D of the line to station I while said line is in use will also result in producing a sound in the telephone-receiver of the operator making the test. It is one of the functions of the lever J, its points j f, and conductors 12 and 12 to assist in maintaining this connection of the conductor 10 of the answer-plug with said terminal of the battery N. For example, when the operator at the left-hand switchboard, Fig. 2, receives a callfor example, from station Iand moves the circuit-changer to bring the operators telephone L into the talking-circuit and then inserts the answer-plug in the respective jack D then the lever K will be on the contact-point k and the contact-pointjof the lever J will be in contact with the plate is on the lever K, whereby the conductor 10 of the said answer-plug will be in connection with the desired terminal of the battery N through the lever J, lever K, conductor 12, and conductor 12. When the operator at said left-hand switchboard has moved the circuit-changer so as to include the clearingout drop in the talking-circuit, (as a loop or bridge therein,} the lever K will rest on the contact-point M, as shown in Fig. 1, and the connection between said lever K and the contact-point j of the lever J will be broken; but at this time the lever J has been moved so as to bring its contact-pointj into engagement with the contact device j, as has been described hereinbefore, and thus the connection of the conductor 10 with the desired terminal of the battery N is still preserved through the lever J, contact devicej branch conductor 12, and conductor 12. Furthermore, when the armature-lever F has been released from the switch-lever E and drawn to the left by the springj", as has been hereinbet'ore described, and the lever J has thereby been moved to close the register-circuit through its contact-point 9' and the contactplate is on the lever K the conductor 10 is still maintained in connection With the desired terminal of the battery N over the lever J, the lever K, and conductor 11, the said lever J, lever K, and conductor 11 thus forming not onlya part of the register-circuit, but also acting as a part of the test-circuit in case at this time any test should be made of the jacks of the line to the calling-station, (station I.) Of course while this connection exists the condenser P is not in the testing-circuit; but this is immaterial, since the telephone-receiver of the operator making the test will be operated by the current actually flowing over the test-circuit at the time of making the test, and thereby said operator will be Warned that the line to station I is in use.

From the above description it will be noted that the talking-circuit is kept entirelyindependent of the register and testing circuits and that no magnets or the like are included in the talking-circuit for actuating the register, but that the magnet G, which performs this function, is in a branch from the talking circuit and that there is no circuit through the said branch while the talkingcircuit is in use, the circuit being closed only momentarily and prior to the closing of the talking-circuit.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a telephone system, the combination with a plurality ofsubstation-conductors, and connector-conductors for completing the connections between said substation-conductors, whereby a talking-circuit is completed, of a branch circuit leading from said talking-circuit, means for closing the-same, a registercircuit, and means operated by the closing of the branch circuit and arranged to close the register-circuit. I

2. Ln a telephonesystem, the combination with a plurality of substation-conductors and connector-conductors for completing the connection between said substation-conductors, whereby a talking-circuit is completed, of a branch circuit leading from said talking-circuit, means at the called substation for closing the branch circuit, a register-circuit and means operated by the closing of the branch circuit and arranged to close the register-circuit. 1

3. In a telephone system, the combination with a plurality of substation conductors and connector-00nd actors for completing the connection betweensaid substation-00nductors, whereby a talking-circuit is completed, of a branch circuit leading from said talking-circuit, a register-circuit, electromagnetic means included in the branch circuit and arranged to close the register-circuit, and means for closing said branch circuit. g

4; In a telephone system, the combination with a plurality of substation-conductors and,

connector-conductors for completing the connection between said substation-conductors whereby a talking-circuit is completed, of a branch circuit leading from one of the said connector-conductors, means at the called substation for closing the branch circuit, a register-circuit, and electromagnetic means located in thebranch circuit and arranged to close the register-circuit.

5. In a telephone system, the combination with a plurality of substation-conductors and connector-conductors for completing the c'onnection between said substation-conductors, whereby a-talking-circuit is completed, of a grounded branch circuit leading from the V talking-circuit, a register-circuit, electromagnetic means in said branch circuit arranged to close the register-circuit, and means at the called substation for grounding one of the substation-conductors, whereby the branch circuit is closed.

6. In a telephone system, the combination with a plurality of substation-conductors and connector-conductors for completing the connection between said substation-conductors, whereby a talking-circuit is completed, of a register-circuit, a grounded branch circuit leading from one of the connector-conductors, an electromagnetic circuit-closer having its coils included in said branch circuit and arranged to close the register-circuit, and means at the called substation forclosingsaid branch circuit.

7. In a telephone system, the combination with a plurality of substation-conductors and connector-conductors for completing the connection between said substation-conductors, whereby a talking-circuit is completed, of a register-circuit, a grounded branch conductor connected to one of the connector-conductors, an electromagnetic circuit-closer having its coils included in the said grounded branch conductor, said circuit-closer being arranged to close the register circuit, a grounded branch conductor at the called substation, and means for closing said substation branch onto the substation-line.

8. In a telephone system, the combination with aplurality of substation-conductors and connector-conductors for completing the connection between said substation-conductors, whereby a talking-circuit is completed, of a register-circuit, a branch circuit leadingjrom said talking-circuit, meansoperated by ,the

closure of said branch circuit and arranged to close the register-circuit, and a telephone I hook-lever at the called station-arranged to momentarily close the branch circuit when moving upward.

9. Ina telephone system, the combination with a plurality of substation-conductors, jacks associated therewith, of a register-circuit normally open at the jacks and at an:

other point, plugs and connector-conductors arranged to enter the respective jacks, one of said pl ugs being arranged to close the register-circuit at the jack into which it is inserted, and one of said connector-conductors being interrupted, of abranch circuit leading i from the interrupted connector-conductor,

electromagnetic meansincluded in the branch circuit and arranged to close both the register-circuit at the second point where it is open and. the interrupted connector-conductor, and means for closing the'braneh circuit.

10. Inatelephone system,thecombination,

with the substation-lines, the jacks associated therewith, the plugs for insertions in said jacks and the plug connector-conductors, one of which is interrupted, of a switch device arranged to close said interruption of the said c0nnector-conduct0r,'a register-circuit open at the jacks and at another point and arranged to be closed at the jack by the insertion of one of said plugs therein, means ,for closing the register-circuit at the other point, said means being held open by the switch device when the latter is in. its open position, retaining mechanism for holding said switch-lever in its open position, and means operated by a called substation for releasing said retaining mechanism, whereby the switch-lever closes its connector-conductor and the means for closing the registercircuit is released to close the same.

11. In atelephone system, the combination, with a plurality of substation-conductors, and connector-conductors for completing the connection between said substation-conductors, whereby a talking-circuit is completed, of a branch circuit leading from the said talkingcircuit and normally open at the central station and at one of the substations, a registercircuit, means for closing the register-circuit, said means being operated by the closing of the branch circuit, means operated at the central station .in making connections between substations for closing the opening at that place in the branch circuit, and means operated by the subscriber at the called station for closing the branch circuit at that point.

12. In a telephone system, the combination, with a plurality of substation-00nductors, and connector-conductors for completing the connections between said substation-00nductors, one of said connector-conductors being interrupted,ofa register-circuitopen at two points, means operated in making connections at the central station for closing the register-circuit at one of said points, and means operated by the called subscriber for closing the interrupted connector-conductor and for closing the register-circuit at the other point where it is open.

13. Inatelephonesystem,thecombination, with apluralityofsubstation-conductors, and connector-conductors for completing the connections between said substation-conductors, whereby a talking-circuit is completed, of a branch circuit, a register-circuit, means at the central station for closing the branch circuit onto the talking-circuit, means at the called substation also for closing the branch circuit onto the talking-circuit, and mechanism 0perated by the closing, at the called substation, of the branch circuit onto the talking-circuit for closing the register-circuit and again opening the branch circuit.

14. In a telephone system, the combination with a jack, 2. register-circuit open at the jack and at a second point, a register included in said circuit, a plug insertible in the jack and arranged to close the register-circuit at that point, a talking-circuit including the plug and jack, and a switch arranged to close the talking-circuit and the register-circuit at the second point, of mechanism for holding the said switch open, an electromagnet arranged to release the switch from said holding mechanism, means operated in completing the connection between substations for engaging the switch with its holding mechanism,and means included in the talking-circuit for actuating the electromagnet to release the switch,wherebythe talking-circuit and the register-circuits are closed. 5

15. In a telephone-exchange, the combination with. a register device, a register-circuit including the register device and the corresponding jacks, of the exchange-plugs provided with means included in the register- 5 circuit for insertion into the respective jacks, whereby the register-circuit is closed at the jacks, a testing-circuit in parallel with the register-circuit, a condenser included in said testing-ci1'cuit,means for energizing both circuits, and means for opening and closing the register and testing circuits alternately.

16. In atelephone-exchange, the combination with a register device, a register-circuit including the register device and the cone 6 sponding jacks, of the exchange-plugs provided with means included in the registercircuit for insertion into the respective jacks, whereby the register-circuit is closed at the jacks, a testing-circuit in parallel with the register-circuit, a resistance included in said testing-circuit, means for energizing both circuits, and means for opening and closing the register and testing circuits alternately.

In testimony whereof I affix my signature in presence of two witnesses.

GEORG BITTER.

Witnesses:

' WALTER ScHWoLBEcH,

JULIUS HEIM. 

